JPH0626416B2 - Double-sided document reader - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a document reading device that receives two-dimensional information on a document surface through a lens into an image sensor and obtains an electrical signal by photoelectric conversion. The present invention relates to a double-sided reading device capable of reading both front and back sides of a document in one operation.

<< Prior Art >> Devices having various structures as shown in FIGS. 11 to 13 have been proposed as a double-sided reading device. In the first conventional example shown in FIG. 11, the document is fed from the automatic paper feed unit 8 to the paper feed path 71,
First turning drum 72, intermediate passage 73, second turning drum 7
4 and the discharge path 75 to transfer to the stacker 6, and the light source 12 is placed at a fixed position facing the turning drums 72 and 74.
First and second fixed reading units 7a and 7b each including a lens 13, a lens 13 and a one-dimensional image sensor 14 are provided, and two-dimensional information on the document surface is first fixed by main scanning by the image sensor and sub-scanning by document movement. The reading unit 7a has a structure in which information on the back surface is read by the second fixed reading unit 7b.

In the second conventional example shown in FIG. 12, the information of the document surface is taken out as optical information by the light source 22 and the reflection mirror 23 mounted on the first carrier 21 which runs along the transparent document table 2,
First and second structures in which images are formed on the one-dimensional image sensor 28 provided at a fixed position through the moving mirrors 25 and 26 mounted on the carrier 24 and the imaging lens 27 provided at the fixed position.
The moving reading units 4a and 4b are provided on the apparatus main body 1 side and the original document holding side 3 respectively, and both sides of an original document placed on the original document table 2 are read by sub-scanning by the carriers 21 and 21 simultaneously or sequentially. Is.

A third conventional example shown in FIG. 13 is provided with a feed belt 5 for transferring a document on the transparent document table 2, an automatic sheet feeding section 8 and a stacker 6, and the document fed on the document table is the same as in FIG. In the device that is read by the simple moving reading unit 4, the reversing drum 76, the pressing rollers 77 and 78, and the V-shaped guide 79
A reversing device 80 consisting of is provided, and the original is fed from the automatic paper feeder 8 onto the transparent original table 2 by the rollers 32, 33, 81 and the belt 5 and the moving reading unit 4 is operated to read the front surface. Next, the original is reversely fed, guided to the reversing device 80, inverted by 180 degrees and fed again onto the transparent original table 2 to read the back side, and the belt 5 and the rollers 82 and 83 stack the read original on the stacker 6. It is of a structure that discharges to.

<< Problems to be Solved by the Invention >> However, in the first conventional example, the length of the document in the sub-scanning direction (feeding direction) is the first and second reading units 7.
If it is longer than the distance between a and 7b, it is necessary to provide a page memory in the document reading device to temporarily store the read information on the front surface or the back surface, which causes a problem that the device cost becomes very high.

Further, in the second conventional example, the page memory can be eliminated by sequentially operating the first reading unit 4a and the second reading unit 4b, but the automatic document feeding becomes completely impossible and the document cover There is a problem in that operability is deteriorated because the size and weight increase.

Further, in the third conventional example, a paper jam is likely to occur in the bent path in the reversing device 80, and thick paper cannot be reversed. Therefore, the paper thickness of an original that can be automatically read or double-sided is limited to a narrow range. There is a problem.

The present invention has been made in view of the above-described problems of the conventional device, and does not require a page memory, has no bent portion in the document passage, and is capable of both automatic paper feed reading and manual insertion reading, and is low. It is an object to obtain a document reading device which is excellent in operability at a price.

<< Means for Solving the Problems >> A double-sided document reading apparatus according to the present invention includes a main body 1 having a transparent document table 2, a document retainer 3 having a feed belt 5 attached to the document table, A moving reading unit 4 having a carrier 21 that is driven to move along a document table; a fixed reading unit 7 arranged on the document entry side or the discharge side of the feed belt to read the opposite surface of the moving reading unit; It is characterized in that an automatic sheet feeding device 8 and a stacker 6 are arranged with a reading section formed by the fixed and moving reading units 7 and 4 interposed therebetween.

Double-sided reading of an original in the above-described apparatus is performed by moving one of the originals by the fixed reading unit 7 while moving the fed original and positioning the original on the transparent original table 2 and then moving the original by the moving reading unit 4. Operation of reading the other side of the document while the first carrier 21 is running in a direction away from the fixed reading unit 7, holding the first carrier 21 of the moving reading unit 4 fixed at a position away from the fixed reading unit 7. Then, the moving reading unit 4 reads the other side of the original while moving the original, or the original is a transparent original while the first carrier 21 of the moving reading unit 4 is moved to a position away from the fixed reading unit 7. Move and read unit 4 after positioning on table 2.
It is possible to sequentially perform the operation by combining the operation of reading the other surface of the document while moving the first carrier 21 in the direction approaching the fixed reading unit 7.

<Operation> The apparatus having the above-described configuration is provided with the fixed reading unit 7 for automatic sheet feeding.
And a so-called flat-bed type moving reading unit 4, one side of which is read by a fixed reading unit and the other side of which is read by a moving reading unit. In addition, the original passage can be formed in a substantially straight line, automatic reading on thick paper or the like is possible, and single-sided reading of a book or the like by manual insertion can be supported. Further, by using the transparent guide as the document guide 11 of the fixed reading unit, it is possible to read a transparent document, and by combining the line memory and the plurality of reading operations, the document can be read in any direction inserted. Data can be output as an appropriate serial signal.

<< Embodiment >> FIG. 1 is a side view showing a first embodiment of the device of the present invention. In the figure, 1 is a main body having a transparent original table 2 on its upper surface, 3 is an original pressing member, the main body 1 has a built-in moving reading unit 4 having the same structure as the conventional one, and the original pressing member 3 is the same as the third conventional example. The feed belt 5 having a different structure is built in. Photoelectric sensors A and D for detecting a document are provided at the sheet entrance end of the feed belt 5 and the sheet discharge side end of the document table, and the stacker 6 is provided so as to extend substantially parallel to the sheet discharge direction of the document table 2. It is installed.

On the other hand, a fixed reading unit including a transparent manuscript guide 11, an illumination lamp 12, a rod lens 13, a one-dimensional image sensor 14, and paper feed rollers 15 and 16 in front of and behind the manuscript guide 11 close to the paper entrance side of the manuscript table 2. 7 is provided. The transparent manuscript guide 11 is disposed on the same plane as the transparent manuscript table 2 and a linear manuscript path is formed between the two, and the first carrier 2 of the moving reading unit 4 is provided.
1 can read a transparent original by moving to a position just below the transparent original guide 11. Photoelectric sensors B and C for detecting a document are provided before and after the paper feed roller 15 on the paper entrance side.

An automatic document feeder 8 is arranged on the paper entry side of the fixed reading unit 7. This automatic sheet feeder has a known structure and is composed of a sheet feed table 31 for stacking and storing originals, a pickup roller 32, and a separation roller pair 33.
The upper roller 33a of the separation roller pair 33 rotates in the paper feeding direction, and the lower roller 33b rotates in the counter paper feeding direction, so that the uppermost portion of the plurality of originals that have entered the nip portion of the separation roller pair 33 is located. Pass only one. The pickup roller 32 and the separation roller pair 33 are connected to the electromagnetic clutch 34 (second
Paper feed roller 15 of the fixed reading unit,
It is connected to 16 and becomes free rotation state by releasing the electromagnetic clutch. Paper feeder 31 of automatic paper feeder
Must be installed so that the leading edges of the stacked documents are aligned in the paper feed direction, but as long as that need is satisfied, the paper should be installed as horizontally as possible and automatic paper feed A large bend is not formed in the document passage between the section and the fixed reading unit.

The above device has a plurality of operation modes, and the operation of each mode will be described below with reference to the drive block diagram of FIG. 2 and the flowchart of each mode.

In the first operation mode shown in FIGS. 3 (a) and 3 (b), when the roller drive motor 41 is rotated with the clutch 34 in the ON state to start automatic sheet feeding, when the sensor B detects the leading edge of the document. When the clutch 34 is turned off, the pickup roller 32 and the separation roller pair 33 are freely rotated, and the original is fed by the distance e (FIG. 1), the fixed reading unit 7
To the reading start command, the belt drive motor 42 is started to rotate when the sensor A detects the leading edge of the document, and the document B is further fed by the distance e after the sensor B detects the passage of the trailing edge of the document. At this point, the fixed reading unit 7 is given a reading end command. Through the above operation, the fixed reading unit 7 reads the front surface of the document. The roller and belt drive motors 41 and 42 continue to rotate, and when the sensor A detects the passage of the trailing edge of the document, the rotation of the roller drive motor 41 is stopped, and at the time when the document is fed by the distance a. The rotation of the belt drive motor 42 is stopped. With the above operation, the document is positioned on the transparent document table 2.

Next, a forward rotation command is given to the carrier drive motor 43, a reading start command is given to the movement reading unit 4 at the same time, and a reading end command is given at the time when the first carrier 21 moves by the sheet length, and the carrier driving motor 43 is given.
And the carriers 21 and 24 return to their home positions. By this operation, the back side of the document is read.
The paper length can be detected by detecting the amount of rotation of the roller drive motor 41 from when the sensor B or A is turned on to when it is turned off. Then, a rotation command is given to the roller drive motor 41 and the belt drive motor 42 next,
After the sensor D detects the passage of the rear end of the document, the distance d is further increased.
After feeding the original document, a stop command is given to the belt drive motor 42. By this operation, the read original is discharged to the stacker 6 and the feeding of the next original is started. By repeating the above operation, the originals on the paper feed table 31 are sequentially read.

According to the above operation mode, the front and back surfaces of the document are read in the main scanning direction indicated by arrows P and Q and the sub-scanning direction indicated by R and S in FIG. 6, so that the top and bottom of the document correspond to the document feeding direction. If this reading mode is used in the orthogonal direction, both the front and back surfaces of the original will be read from left to right and from the top to the ground. However, if the top and bottom of the document match the feed direction of the document, in the first operation mode, the front side of the document is read from the top to the ground and right to left, and the back side is read from the ground to the top. The data is read upside down from left to right, and it becomes necessary to provide a page memory and invert the data for one page. Therefore, in such a case, the following second or third operation mode is selected.

In the second operation mode shown in FIG. 4, the first carrier 21 is first moved to the position of the sensor D. And the first
After the front surface is read by the same procedure as the mode (steps 61 to 62 in FIG. 3), the belt drive motor 42 continues to rotate even after the sensor A detects the trailing edge of the document, and the leading edge of the document is read. Is detected by sensor D, carrier 2
While the number 1 is fixed, a reading start command is given to the moving reading unit 4, and when the sensor D detects the trailing edge of the document, the reading is ended and a driving command is given to the roller driving motor 41 to feed the next document. Then, the belt drive motor 42 is stopped when the document is transported by the distance d.

In the third operation mode shown in FIG. 5, the first carrier 2
1 is first moved to the position of the sensor D, the surface is read in the same procedure as in the first mode (steps 61 to 62 in FIG. 3), and then the sensor D detects the front end of the document. Then, the belt drive motor 42 is stopped, the reverse rotation of the carrier drive motor 43 is started, and a reading start command is given to the movement reading unit 4, and when the first carrier 21 moves by the length of the sheet, the movement reading unit 4 is moved.
Is given a read end command and the carrier drive motor 43 is rotated in the forward direction to return the first carrier 21 to the position of the sensor D. After that, the reference numerals 63 to 6 of the first operation mode
Similarly to the steps up to 4 (FIG. 3 (b)), the rotation command is given to the roller drive motor 41 and the belt drive motor 42,
After the sensor D detects the passage of the rear end of the document, the distance d is further increased.
The belt drive motor 42 is stopped after the original is sent.

According to the second and third operation modes, as shown in FIG. 7, both the front and back sides of the document can be read from the top to the ground when the top and bottom of the document match the document feeding direction. Becomes Since the scanning directions of the image sensors 14 and 28 are constant, the main scanning direction P of the front surface of the document is reversed from the right side to the left side of the document in the second and third operation modes in the illustrated apparatus. . This problem can be solved by providing the line memory 44 in the apparatus and inverting the read data on the surface one read line at a time, and it is possible to deal with the problem with a small-capacity memory, which leads to an increase in treatment cost and a delay in signal processing. There is no. The second mode and the third mode are
It suffices to provide either one of the operation modes, and if the paper feed accuracy of the feed belt 5 becomes a problem due to slip, the third operation mode may be selected.

8 and 9 show a second embodiment of the device according to the present invention, in which the fixed reading unit 7 and the moving reading unit 4 are shown.
By using the image sensor and the imaging lens in common, the cost is reduced. Only the parts different from the first embodiment will be described below.

In the second embodiment, the lens holder 51 having the image sensor 28 and the imaging lens 27 is mounted on the carrier 2.
The movable reading position M and the fixed reading position N can be positioned by using, for example, a stepping motor and a ball screw. The holding plate 52 of the mirror 26 below the second carrier 24 is pivotally supported by a pin 53 on the carrier as shown in FIG.
The spring 54 presses and holds it in the position shown by the solid line in the figure. On the other hand, the holder 51 includes a mirror holding plate 5
The second carrier 2 is provided with a protrusion 55 facing the second direction.
When 4 is at the home position in the drawing and the holder 51 has moved to the fixed reading position N, the projection 55 pushes the mirror holding plate 52 and causes the mirror 26 to fall down to the position shown by the imaginary line in FIG.

The optical path of the fixed reading unit 7 is formed by the mirrors 56 and 57 fixed to the document holder 3 and the mirror 58 fixed to the main body 1, and the information of the document passing through the transparent document guide 11 is located at the fixed reading position N in the image sensor 28. Image. At this time, the lower mirror 26 of the second carrier is laid down as described above, and does not block the optical path.

Also in the apparatus of the second embodiment, the reading operation in the first, second and third modes is possible as in the first embodiment,
As shown in FIG. 10, the moving operation of the holder 51 is only inserted between the fixed reading (front surface reading) and the moving reading (back surface reading).

<Effects of the Invention> According to the present invention described above, sequential reading of both sides of a document can be performed without using a page memory regardless of the relationship between the top-bottom direction of the document and the feeding direction. It is possible to reduce the cost. In addition, since the problem that the weight of the document holder becomes large does not occur, the operability of flatbed reading by manual insertion is not deteriorated, and manual reading of documents including books and the like, and automatic feeding of sheet documents are performed. All reading operations of single-sided reading and double-sided reading are possible. Further, since there is no bend in the paper path, it is possible to automatically read originals that are not easily bent, such as thick paper, and it is possible to provide a compact, multifunctional and low-priced original reading device.

[Brief description of drawings]

1 to 5 are views showing a first embodiment of the present invention. FIG. 1 is a sectional view showing an essential part of the apparatus, FIG. 2 is a block diagram showing an essential part drive system, and FIG. (a) and (b) are flowcharts showing the first reading method, FIG. 4 is a flowchart showing the second reading method, and FIG. 5 is a flowchart showing the third reading method. FIG. 6 and FIG. 7 are views for explaining the relationship between the top-bottom direction of the document, the feeding direction, and the main scanning and sub-scanning directions. 8 to 10 are views showing a second embodiment, FIG. 8 is a sectional view of the entire apparatus, FIG. 9 is an enlarged side view of the second carrier, and FIG. 10 is a flow chart showing only essential parts. Is. 11 to 13 show first to third.
It is sectional drawing which shows a prior art example. In the figure, 1: body, 2: transparent document table 3: document holder, 4: moving reading unit 5: feed belt, 6: stacker 7: fixed reading unit, 8: automatic paper feeder 11: transparent document guide, 12: Illumination lamp 13: Rod lens, 14: Image sensor 21: First carrier, 22: Light source 24: Second carrier, 27: Lens 28: Image sensor, 31: Paper feed stand 44: Line memory

Claims (5)

[Claims] 1. A main body (1) provided with a transparent document table (2), and a document retainer (3) provided with a feed belt (5) covered with the document table.
And a moving reading unit (4) provided with a carrier (21) that is driven to move along the document table, and a reading surface opposite to the moving reading unit disposed on the document entry side or the discharge side of the feed belt. An original document in which a fixed reading unit (7) and an automatic sheet feeder (8) and a stacker (6) are arranged with a reading section formed by the fixed and moving reading units (7) and (4) interposed therebetween. Double-sided reading device. 2. An image sensor (14) or (2) is attached to either the fixed reading unit (7) or the moving reading unit (4).
The double-sided reading device according to claim 1, further comprising a line memory (44) for inverting bit information of one reading line read in 8). 3. An operation of reading one side of a document by a fixed reading unit (7) while moving the fed document, and positioning the document on a transparent document table (2) and then moving the reading unit (4). 3. The operation of reading the other side of the document while the carrier (21) of () is running in the direction away from the fixed reading unit (7) is performed as a sequential operation.
Or the double-sided reading device described in 2. 4. A fixed reading unit for moving a document.
Move one side of the document with (7) and move while moving the document while holding the carrier (21) of the moving reading unit (4) at a position away from the fixed reading unit (7). The reading unit (4) performs the operation of reading the other surface of the document as a sequential operation.
Or the double-sided reading device described in 2. 5. An operation of reading one side of a document by a fixed reading unit (7) while moving a fed document, and a carrier (21) of the moving reading unit (4) from the fixed reading unit (7). Position the original on the transparent original table (2) while moving it to a distant position, and then move the carrier (21) of the moving reading unit (4) while moving it toward the fixed reading unit (7). The double-sided reading device according to claim 1 or 2, wherein the operation of reading the other surface of the above is performed as a sequential operation.